function test() {
  let age

  function setage(v) {
    if (typeof v === 'number') {
      if (v > 0 && v <= 100) {
        age = v
      } else {
        age = 20
      }
    } else {
      age = 20
    }
  }

  function getage() {
    return age
  }

  return {
    setage,
    getage
  }
}

let obj = test()
obj.setage(400)
console.log(obj.getage())
